Vaccines and process for manufacturing vaccines



Patented Dec. 14, 1937 UNITED STATES VACCINES AND PROCESS FOR- MANUFAC- TURING VACCINES Marion Dorset, deceased,

- late of Washington,

D. C., by Virgil Jackson Dorset, administrator,

Washington, D. 0., as

lace, as Secretary'ot States of America.

No Drawing. Application Jim, 15. 1936,

Serial No.

ignor to Henry A. Wall cnlture oi the United 2 Claims. (01. 167-80) I (Granted underthe m of March 3,1883, as

amended April 30, 1928; 370 0. G. 757) This application ismade under the act of March 3, 1883, as amended by the act of April 30, 1928, and the invention herein described, if patented, may be manufactured and used by or 5 for the Government for governmental purposes without the payment of any royalty thereon.

This invention relates to vaccines and process for manufacturing vaccines.

Certain diseases of man and other animals are self-limiting. Introduction of matter carrying the infection of such a disease into the animal organism in such a manner as to cause an attack of the disease also stimulates the animal organism to produce anti-bodies which oppose the disease-producing effect of the infectious matter upon the organism. As a result of the production of anti-bodies the progress ofthe disease is mitigated, arrested or terminated. Incase the animal survives, these anti-bodies persist in its body for a significant period and therefore afford a significant degree of protection or immunity against another attack of the disease when the animal is againexposed to infection.

In the case of any disease of the nature described above it is theoretically possible to manufacture a substance, technically known as a vaccine, which, when properly administered to an animal, will notably stimulate the production of anti-bodies in its organism without at the same time producing a characteristic attack of the disease itself, although it may produce certain comparatively mild and temporary disturbances. It is well known that the manufacture of vaccines against several diseases has been re- 5 duced to practice and that the products are widely and successfully employed. The principle upon which vaccines may be prepared is well understood. Infectious matter in appropriate physical condition is subjected to such treatment,

which may be either physical or chemical in nature, or a combination of both, that its power to produce disease is mitigated or destroyed while at the same time its power to stimulate the production of anti-bodies in the animal organism is left comparatively unimpaired. It is further well known that any process that has been proved useful for the manufacture of a vaccine against a specific disease from its specific infectious matter is likely to be useful for the manufacture of a vaccine against some other specific disease from its specific infectious matter, although the optimal conditions of concentration, temperature and time-periods may differ somewhat in I For example, the substance as well known useful chemical different cases. formaldehyde is agent for the manufacture of vaccines against several diseases.

The invention deals with a process for preparing vaccines through useof a chemical attenuating agent not hitherto employed for the pur- 5 pose. It was discovered that the chemical substance hexa-methyl pararosaniline in'solution or in the form of a salt thereof is capable of destroying the disease producing power of infectious matter without depriving it of power to 10 stimulate the formation of anti-bodies and to produce immunity against the disease. The invention, therefore, consists simply in treating infectious matter. with hexa-methyl pararosaniline in solution or a salt thereof in. such strength and 15 for such a time as to rob the material of power to produce disease without seriously impairing its power to bring about immunity. Favorable results have been obtained by employing hog cholera virus, cultures of Salmonella suipestifer 20 and cultures of Brucella abortus as initial infectious matter. However, here is described in detail only the manufacture of vaccine against hog cholera.

A 5000 parts of virulent defibrinated virus 25 blood drawn ,from swine sick with. hog cholera preferably between the seventh and ninth days, inclusive, after exposure of the swine to disease by appropriate virus injection, is added, with agitation, between 1 and 3 parts of a water- 30 soluble salt of hexa-methyl pararosaniline previously dissolved in water. A convenient salt for the purpose is the hydrochloride, which is commercially available as the dye commonly termed crystal violet. A 1 percent aqueous solution of 35 crystal violet is appropriate. In practice, though this is not an essential part of the process, it is found advantageous to add also about 5 parts ofv benzophenol, C8H5OH, best in the form of a strong aqueous solution, in order more certainly 0 to preclude spoilage of the product by bacteria. Other antiseptics might be used. The mixture is kept in an incubator or other storage space preferably at a temperature near 375 C. until tests by injection into susceptible swine show that 45 it has become deprived of power to produce disease, which is usually effected within a period of two weeks. The material, vis then withdrawn from the'incubator and is thereafter stored in a reasonably cool place, as in an ordinary refrig- 50 erator. It will be understood that sources of virus other than 'defibrinated blood may be employed, such as citrated or oxalated blood, or appropriate extracts from various other tissues or organs from which virus is obtainable. The tem- 55 perature of manufacture is not necessarily restricted to near i875 C. It may be higher or lower, but in such case it will be found that the period necessary to effect attenuation will be inversely proportional to the temperature maintained. The vaccine is applied by subcutaneous or'intraperitoneal injection into the swine to be protected or immunized. One dose is usually sufficient. The size of the. dose will depend upon such factors as the weight and age of the swine and the potency of the particular lot of vaccine. Therefore each lot of vaccine should be tested for potency and the dose correspondingly set or standardized before the vaccine is put to actual use. Additionaldoses may, however, be subsequently applied. Swine treated with this vaccine do not, as a rule, acquire immunity immediately;

however, the immunity becomes firmly established in three weeks. Therefore, in performing the test for potency above referred to, the susceptible swine used in the test are to be left three weeks after vaccine injection before receiving .a virus injection in manner and amount suflicient to initiate a severe attack of hog cholera if they had not been protected or immunized by the vaccine. r

Having fully disclosed the invention, it is claimed:

1. A process for the manufacture of vaccine against hog cholera which comprises mixing together -virulent defibrinated virus blood from swine sick with hog cholera with from 1/50 to 1/17 of its volume Ma 1 per cent aqueous solution of crystal violet, and maintaining the mixture at near-37.5 C. for approximately two weeks, until the material becomes incapable of transmitting hog cholera when injected into susceptible swine.

2. A process for the manufacture of vaccine against hog cholera which comprises mixing together virulent deflbrinated virus blood from swine sick with hog cholera with from 1/50 to 1/17 of its volume of a 1 per cent aqueous solution of crystal violet, and an antiseptic, and maintaining the mixture at near 37.5 C. for approximately two weeks, until the material becomes incapable of transmitting hog cholera when injected into susceptible swine.

vmon. JACKSON DORSET, Administrator of the Estate of Marion Dorset,

Deceased. 

